Add fastcgi_cache to NginX

I wanted to try enabling fastcgi_cache as demonstrated in this guide:

https://rtcamp.com/wordpress-nginx/tutorials/single-site/fastcgi-cache-with-purging/

Support for this feature is not enabled in the Ajenti-V installed NginX. Is there an easy to way to add this in or replace ajenti-v nginx with my own nginx while maintaining compatibility with updates to Ajenti? Thank you so much!